Shadow Trap

Necrotic Spell, Tier 1, 2 Actions, Single Target

Concentration: Up to 1 minute. The next creature to move adjacent to you suffers 3d12 damage; if Small or Tiny, it is also Restrained by shadowy tendrils for as long as you maintain concentration or until they escape. Upcast: +1 size category, +1d12 damage when they escape.

From Core Rules